Easy guide on how an automotive universal joint works ("U" joint) this information pertains to most rear and four wheel drive vehicles.
A universal joint or "U" joint as it is sometimes called, is used to connected two rotating objects together while on different plains, these U joints are used commonly in the automotive industry.
An "U" joint is used at the rear of the vehicle and is connected to the differential via the drive shaft.
A duplicate (in most cases) U joint is located at the opposite side of the driveshaft
which is connected to the transmission or transfer case (four wheel drive).